| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame] | 1 | From b2f7c18c351737c2a053c39c09ef50870fd78c06 Mon Sep 17 00:00:00 2001 |
| 2 | From: Vladimir Oltean <vladimir.oltean@nxp.com> |
| 3 | Date: Thu, 14 Nov 2019 17:03:25 +0200 |
| 4 | Subject: [PATCH] net: mscc: ocelot: adjust MTU on the CPU port in NPI mode |
| 5 | |
| 6 | When using the NPI port, the DSA tag is passed through Ethernet, so the |
| 7 | switch's MAC needs to accept it as it comes from the DSA master. Increase |
| 8 | the MTU on the external CPU port to account for the length of the |
| 9 | injection header. |
| 10 | |
| 11 | Without this patch, MTU-sized frames are dropped by the switch's CPU |
| 12 | port on xmit, which is especially obvious in TCP sessions. |
| 13 | |
| 14 | Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> |
| 15 | Reviewed-by: Andrew Lunn <andrew@lunn.ch> |
| 16 | Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> |
| 17 | Signed-off-by: David S. Miller <davem@davemloft.net> |
| 18 | --- |
| 19 | drivers/net/ethernet/mscc/ocelot.c | 9 +++++++++ |
| 20 | drivers/net/ethernet/mscc/ocelot.h | 2 ++ |
| 21 | 2 files changed, 11 insertions(+) |
| 22 | |
| 23 | --- a/drivers/net/ethernet/mscc/ocelot.c |
| 24 | +++ b/drivers/net/ethernet/mscc/ocelot.c |
| 25 | @@ -2229,9 +2229,18 @@ void ocelot_set_cpu_port(struct ocelot * |
| 26 | * Only one port can be an NPI at the same time. |
| 27 | */ |
| 28 | if (cpu < ocelot->num_phys_ports) { |
| 29 | + int mtu = VLAN_ETH_FRAME_LEN + OCELOT_TAG_LEN; |
| 30 | + |
| 31 | ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPUQ_MSK_M | |
| 32 | QSYS_EXT_CPU_CFG_EXT_CPU_PORT(cpu), |
| 33 | QSYS_EXT_CPU_CFG); |
| 34 | + |
| 35 | + if (injection == OCELOT_TAG_PREFIX_SHORT) |
| 36 | + mtu += OCELOT_SHORT_PREFIX_LEN; |
| 37 | + else if (injection == OCELOT_TAG_PREFIX_LONG) |
| 38 | + mtu += OCELOT_LONG_PREFIX_LEN; |
| 39 | + |
| 40 | + ocelot_port_set_mtu(ocelot, cpu, mtu); |
| 41 | } |
| 42 | |
| 43 | /* CPU port Injection/Extraction configuration */ |
| 44 | --- a/drivers/net/ethernet/mscc/ocelot.h |
| 45 | +++ b/drivers/net/ethernet/mscc/ocelot.h |
| 46 | @@ -65,6 +65,8 @@ struct frame_info { |
| 47 | #define IFH_REW_OP_ORIGIN_PTP 0x5 |
| 48 | |
| 49 | #define OCELOT_TAG_LEN 16 |
| 50 | +#define OCELOT_SHORT_PREFIX_LEN 4 |
| 51 | +#define OCELOT_LONG_PREFIX_LEN 16 |
| 52 | |
| 53 | #define OCELOT_SPEED_2500 0 |
| 54 | #define OCELOT_SPEED_1000 1 |